but a joyride, bringing brandon joy and, well, eventually, a nap. but for one special bystander, brandon's uncle, all of this isn't just about granting a wish. it's about saving a life. and you're playing a real special part in all of this, right? >> i'm the actual donor. and i've decided to come forth with this after seeing what he's been going through. >> reporter: he will soon be giving the ultimate gift, one of his kidneys, to his nephew, brandon. but today isn't about hospitals. it's about hope. and a wish come true for the happiest little firefighter ever. for "good morning america," abbie boudreau, abc news, los angeles. >> and that's the kind of thing these letters can do. thanks, macy's. by the way, a little drumroll, as we tell you. it's incredible. the total, 744,838 letters. >> that's awesome. >> that has translated into dollars since macy's is kicking in a dollar for every letter. it's national believe day. they're going to grant 70 wishes across the country today. but also, they're going to double every letter that is stamped and colle